The ram material is then again raised and a further corresponding zero point is stored beforehand. In accordance with the method, a compaction progress that takes place is then determined and stored and the previous steps are repeated until the compaction progresses of a specific number of consecutive compaction procedures are smaller than or equal to a predefined minimum progress.
It is known to provide the operator of a soil compaction machine or of a base machine for soil compaction with a specification of how many defined blows are required for a corresponding soil compaction has to be carried out. Preparatory calculations are required for this purpose with reference to which a number of blows required for soil compaction is determined in dependence on the soil properties of the soil to be compacted.
It is alternatively or additionally also possible to dynamically determine whether an achieved degree of compaction is sufficient by means of a measurement. It can accordingly be determined whether further blows or compaction work are required. However, disadvantageously, additional equipment is required to carry out the measurements. This represents an increased effort both in procurement of the corresponding equipment and in its use.
It is therefore the object of the present disclosure to provide a method of soil compaction, wherein in particular no additional measurement systems are required to determine the compaction progress and wherein a simplified apparatus can be used.
This object is achieved in accordance with the present disclosure by a method of soil compaction by means of a base machine, wherein the base machine comprises ram material provided at at least one cable and a control/regulation apparatus and wherein the method comprises the following steps:                raising the ram material from the land area to be compacted, with a zero point being stored at which no slackline is present;        raising the ram material to a lift height;        carrying out a compaction procedure by dropping the ram material from a drop height onto the land area to be compacted;        a repeat raising of the ram material from the land area to be compacted, with a further zero point being stored at which no slackline is present;        determining and storing a compaction progress; and        repeating the previous steps until the compaction progresses of a predefined number of consecutive compaction procedures are smaller than or equal to a predefined minimum progress.        
The term slackline here means that the cable carrying the ram material is not completely unloaded, but that rather at least some of the weight force of the ram material is carried by the cable. The cable is thus at least partially tensioned by the weight force of the ram material and thereby sags as a slackline or as an unloaded cable. It is decisive for the determination of the zero points that no slackline is present at the time of the measurement or of the saving of the zero point since otherwise it would not be possible to determine the correct zero point and thus not the correct distance between, for example, the zero point and the lift height. The zero point can in this respect, for example, be determined or saved as a function of the length of the unreeled or reeled up cable.
The terms of the zero point and of the compaction progress will be defined in more detail in the embodiment described further below. The predefined number of consecutive compaction procedures can be input at the regulation/control apparatus (e.g., at a user interface of the regulation/control apparatus) by an operator. It is also conceivable that this number is stored in the regulation/control apparatus and/or is polled from it and has to be input accordingly by an operator. The same applies to the predefined minimum progress that can be indicated by the operator or that can alternatively or additionally be stored in the regulation/control apparatus (e.g., stored in non-transitory memory of the regulation/control apparatus).
It is conceivable in one embodiment that the process displays and/or is ended when the compaction progresses of a predefined number of consecutive compaction procedures are smaller than or equal to a predefined minimum progress. The compaction can thus be automatically ended in accordance with the process when a desired degree of compaction of the soil has been reached. The reaching of a desired degree of compaction is in this respect a function of the input or stored minimum progress and of the predefined number of compaction procedures required for this purpose. Provision can also be made in accordance with the process that only the reaching of the corresponding degree of compaction is displayed to the operator, for example via a display of the regulation/control apparatus.
It is conceivable in a further embodiment that the zero point is determined by a zero calibration and/or is detected by a sensor system. The zero point can thus, for example, be set manually by an operator in that the ram material is placed onto the ground and the cable that bears the ram material is tautened without raising the ram material from the ground. This position of the ram material corresponds to the zero point and can be associated with the cable length that is unreeled or reeled up in this process. The zero point can also be detected automatically via a corresponding sensor system, with the ram material likewise being able to be placed on the subsurface and with it being able to be determined by means of the sensor system whether the cable that bears the ram material is loaded or tautened and thus no slackline is present. A zero point and its corresponding cable length can thus also be detected automatically.
It is conceivable in a further embodiment that the sensor system for detecting the zero point measures the power of a winch motor of the base machine and/or load measurement signals of the load at the cable, in particular by means of load measuring pins in cable pulleys and/or strain measuring cells in or at the cable or in cable struts. Devices or sensors typically present at the base machine can thus be used for determining the zero point and an additional and disadvantageously expensive and complex provision of corresponding devices is advantageously not necessary.
It is conceivable in a further embodiment that the lift height of the ram material is determined automatically or is set manually via a cable length measurement, in particular via the number of revolutions of the hoisting winch. It is furthermore conceivable that the lift height is constant for all compaction procedures. It can thus be ensured that the same energy is introduced into the land area on every compaction procedure and that a uniform compaction can thereby take place.
It is conceivable in a further embodiment that the cable is braked during, before and/or after the landing of the ram material on the land area to be compacted. A slacking line can thereby be effectively prevented or reduced and the compaction can thus be carried out in an accelerated manner.
It is also conceivable in an embodiment to also repeat the method described above when a permitted tolerance is fallen below or exceeded on wall collapses (Ytol). It is accordingly possible in accordance with the method to automatically take any wall collapses into consideration so that an intervention on the part of the operator of the base machine is not necessary here.
The present disclosure is also directed to an apparatus, in particular to a cable-operated excavator or a rammer that is configured to carry out the methods of soil compaction described herein. The apparatus can in particular comprise devices for determining the zero points, devices for measuring the power of the winch motor, devices for the load measurement of the load at the cable, in particular load measuring pins and/or strain measuring cells, and/or devices for measuring the cable length.
Further details and advantages of the present disclosure will be shown with reference to the Figures.